Photodetector having high speed and sensitivity

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

357 16, 357 61, 357 88, 357 90, H01L 2714, H01L 29161, H01L 29205

Patent

active

050518046

ABSTRACT:
The present invention provides a photodetector having an advantageous combination of sensitivity and speed; it has a high sensitivity while retaining high speed. In a preferred embodiment, visible light is detected, but in some embodiments, x-rays can be detected, and in other embodiments infrared can be detected. The present invention comprises a photodetector having an active layer, and a recombination layer. The active layer has a surface exposed to light to be detected, and comprises a semiconductor, having a bandgap graded so that carriers formed due to interaction of the active layer with the incident radiation tend to be swept away from the exposed surface. The graded semiconductor material in the active layer preferably comprises Al.sub.1-x Ga.sub.x As. An additional sub-layer of graded In.sub.1-y Ga.sub.y As may be included between the Al.sub.1-x Ga.sub.x As layer and the recombination layer. The recombination layer comprises a semiconductor material having a short recombination time such as a defective GaAs layer grown in a low temperature process. The recombination layer is positioned adjacent to the active layer so that carriers from the active layer tend to be swept into the recombination layer. In an embodiment, the photodetector may comprise one or more additional layers stacked below the active and recombination layers. These additional layers may include another active layer and another recombination layer to absorb radiation not absorbed while passing through the first layers. A photodetector having a stacked configuration may have enhanced sensitivity and responsiveness at selected wavelengths such as infrared.

REFERENCES:
patent: 4254429 (1981-03-01), Yamazaki
patent: 4378259 (1983-03-01), Hasegawa et al.
patent: 4383269 (1983-05-01), Capasso
patent: 4473835 (1984-09-01), Forrest et al.
patent: 4475477 (1984-10-01), Capasso et al.
patent: 4553155 (1985-11-01), Chen et al.
patent: 4590507 (1986-05-01), Capasso et al.
patent: 4694318 (1987-09-01), Capasso et al.
patent: 4816082 (1989-03-01), Guha et al.
patent: 4933728 (1990-06-01), Fukuzawa et al.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Photodetector having high speed and sensitivity does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Photodetector having high speed and sensitivity, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Photodetector having high speed and sensitivity will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-1700600

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.